Dear Dr. Gridlock:

The folks who use the Foggy Bottom Metro waited a long time for the new escalators. The new escalators have been in place for many weeks now. Two of the three escalators ascend during the morning rush, as it should be.

However, two of those three escalators still ascend during the evening rush when they should be reversed. Many times in the evening rush, a queue backs up down 23rd Street waiting to descend the one down escalator. What is up with that?

— Terry Girone, Oakton

This isn’t the whim of a station manager or someone being forgetful about switching directions. Metro is making a choice about the directions, and riders see this not only at Foggy Bottom but also at other stations where three escalators connect the platform and mezzanine or the mezzanine and the street.

Most riders I hear from would agree with Girone about what should happen, and they probably will find the Metro strategy counterintuitive. But I’m curious to hear their views.

The transit staff thinks that at many stations it should keep two escalators going up and one going down, regardless of the time of day.

There are several reasons for that, Metro spokesman Dan Stessel said in an e-mail. Most of them have to do with traffic management. People tend to go down faster than they go up, so as long as one escalator is working in the down direction, there shouldn’t be a serious delay.

(If you look back at Girone’s letter, you’ll see that at least one rider disagrees with that.)

Further, Stessel said, Metro sees a difference in the way people get in and out of the stations. Even at peak periods, people spread out their arrivals at the station entrances.

Compare that to how people already on the trains arrive at the platform: A six-car or eight-car trains opens its doors all at once and the riders pour out onto the platform.

Depending on the line and the station configuration, two trains may be unloading passengers at the same time onto already crowded platforms. That would be particularly likely during rush hours in downtown D.C. along the tunnel where the Blue and Orange Line trains travel together.

It’s important to deal immediately with that surge into a confined space, and get those passengers off the platforms as quickly as possible, both for safety reasons and as a matter of service.

Stessel also cited a reason for the policy that’s become painfully obvious to many riders: Metro escalators are fragile. Frequent changes in the escalators’ direction make them more likely to break down over time, he said.

My take, based in part on observations along the Blue and Orange lines during this morning’s rush: I think that out of the two goals — getting people in efficiently and getting them out efficiently — it’s more important to get them out efficiently.

Being on a crowded platform at Navy Yard for a Nationals game, or at Gallery Place for a Capitals or Wizards game, can get your attention on this.

At those places, Metro generally has extra staff to help control crowds and monitor the platforms. Right now, Metro has an extra force of staffers and transit police at the Dupont Circle station to monitor crowding and adjust to it, because the south entrance closed this week.

But that’s not typical. I don’t believe a station manager — the person who might be out helping a tourist family understand the fare vending machines — is going to be able to constantly monitor the ebb and flow of crowds at the escalators.

If Metro has to rely on a formula, it would be better to give priority to getting people out of the tight space of the station rather than into it.

The part of the strategy I like least is what it says about the overall condition of the escalators. Station managers should have the flexibility to reverse directions on the escalators without worrying that they will bust the moving parts and force people to walk up and down stopped escalators.

This is one reason I’m encouraged about Metro’s decision, reflected in its new capital budget proposal, to replace rather than rehabilitate nearly 100 of these ill-fated machines.

So what’s your take, both on the theory and the practice of escalator operations?

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